In recent years, the development of wireless power-transmitting systems capable of wirelessly supplying electric power from a power-supplying side to a power-receiving side has been actively conducted. The wireless power-transmitting system is convenient since the wireless power-transmitting system can supply electric power without a connection using a wiring (a cable) between the power-supplying side and the power-receiving side. Therefore, the wireless power-transmitting system has promise for application to charging a battery mounted in a vehicle such as an electric vehicle (EV) or a plug-in hybrid electric vehicle (PHEV).
In the wireless power-transmitting system used for charging the battery mounted in the vehicle, for example, a wireless power-transmitting device is installed in each parking area (parking region) set within a parking facility, and electric power is wirelessly supplied to the vehicle parked in the parking area. In general, because a plurality of parking areas are provided in the parking facility and the vehicle can be parked in each parking area, it is necessary to associate the wireless power-transmitting device configured to supply electric power with the vehicle configured to receive the electric power from the wireless power-transmitting device.
The following Patent Document 1 discloses a power-transmitting system for wirelessly transmitting electric power to all indoor electric devices although this power-transmitting system is not used for charging a battery mounted in the vehicle. Specifically, in the power-transmitting system of the following Patent Document 1, the electric power is supplied to the indoor electric device through light, and the transmission and reception of necessary information to and from the electric device is performed through light. Alternatively, the electric power is supplied to the indoor electric device through radio waves, and the transmission and reception of necessary information to and from the electric device is performed through radio waves.
The following Patent Document 2 discloses a power-supplying system for wirelessly supplying electric power to a vehicle parked in a parking area. The power supply system of Patent Document 2 includes a power-receiving unit provided on a bottom of the vehicle, a power-transmitting unit embedded in the parking area, a transmitting unit and a receiving unit installed in the vehicle, and a transmitting unit and a receiving unit installed in the parking area. When a request-for-charging signal transmitted from the transmitting unit of the vehicle side is received by the receiving unit of the parking area side, charging to the battery mounted in the vehicle starts. In order to prevent positional misalignment between the power-transmitting unit and the power-receiving unit, the gain, directivity, and the like of an antenna constituting the transmitting unit or the receiving unit are appropriately adjusted. The transmitted and received signal is a radio wave signal or light signal.
The following Patent Document 3 discloses a wireless system for performing wireless communication between an in-vehicle device mounted in the vehicle and a communication antenna device of a roadside unit. The in-vehicle device is mounted on a dashboard inside the vehicle near the windshield of the vehicle. The communication antenna device of the roadside unit is attached to, for example, an upper portion of a pole so that a radiation surface of the communication antenna device inclines at a predetermined angle from a horizontal direction. Thereby, a desired communication region is formed on a road.
In the following Patent Document 4, a wireless charging system for charging a battery by wirelessly transmitting electric power from a charging device to a charging target device such as a vehicle is disclosed. The charging device includes a plurality of charging areas and a plurality of primary power-transmitting coils provided in each charging area. An area identifier (ID) for specifying a charging target device as a power transmission target is allocated for each charging area. The charging device transmits the allocated area ID to the charging target device. The charging target device replies to the transmitted area ID, so that the charging device identifies the charging target device as the power transmission target and wirelessly transmits electric power to the identified charging target device.